Backstepping Sliding Mode Control Based on Extended State Observer for Robotic Manipulators with LuGre Friction

In this paper, we propose a backstepping integral nonsingular fast terminal sliding mode control approach based on an extended state observer to the trajectory tracking control of robotic manipulators with LuGre friction. In order to improve convergence speed and tracking precision, an integral fast terminal sliding surface is introduced. An appropriate saturation function is designed in the control input to avoid singularity. An extended state observer is employed to estimate the uncertainties and disturbances, and they are compensated by the control laws, for which the chattering can be effectively eliminated. The backstepping method is used to design the control input of the system to ensure the globally asymptotic stability based on the Lyapunov criterion. In comparison with other control methods, simulation results show effectiveness and superiority of this proposed control scheme.